A survey of the literature indicated a lack of understanding of the barrier properties of human gingiva for drug delivery with no systematic study on its permeability. This knowledge is essential to the development of effective systems for local drug delivery to the gingiva and surrounding tissues. For example, the gingiva is involved in oral diseases such as periodontitis. Periodontal diseases can lead to tooth loss, complications such as osteomyelitis and facial cellulitis, and bacteria invasion to systemic health in patients at advanced stages of the diseases. The diseases affect approximately half of the population 50 years of age and older in the world. Current therapies are interventions such as scaling and root planning, which are invasive and moderately effective. Existing drug treatments include topical drug application and sustained drug delivery systems for local delivery of antibacterial and anti-inflammatory. Topical drug delivery methods are not very effective due to the dilution and rapid elimination of the drugs in the oral cavity and the gingival tissue barrier for drug permeation. Sustained drug delivery systems are administered by a dentist and only last for a short duration (e.g., up to two weeks). A convenient and effective in-home method for local treatment of chronic periodontal diseases is not available. The present project is divided into two parts: basic research to characterize the barrier properties of the gingiva and translational research to develop an iontophoretic drug delivery method for the gingival tissues. Iontophoretic delivery is a method that has been used in dentistry but has not been fully utilized in oral care. In the first part of the project, the objectives are to characterize the barrier properties of the gingiva and mechanistically study the transport behavior of gingival iontophoretic drug delivery. The transport barrier of human gingiva will be characterized using model permeants/drugs under passive and iontophoretic conditions in vitro. In the second part of the project, an iontophoresis method for gingival drug delivery will be developed and tested in vitro. This includes the construction of the iontophoresis device and testing of the drug formulations. The systematic characterization of the barrier properties of human gingiva in this project will provide the knowledge framework for the present and future gingival drug delivery studies. The successful development of an iontophoretic delivery system not only can provide a new convenient in-home use approach for periodontal diseases but also can be a platform for other oral treatments. The research project will expose undergraduate and graduate students to research in the areas of biomembrane characterization for drug delivery, drug delivery kinetics, and medical device engineering.